summaryrefslogtreecommitdiff
path: root/drivers/mtd/nand/davinci_nand.c
blob: be9d666b6824eb8bdeaae3168e0d68ca2ef7162b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
/*
 * NAND driver for TI DaVinci based boards.
 *
 * Copyright (C) 2007 Sergey Kubushyn <ksi@koi8.net>
 *
 * Based on Linux DaVinci NAND driver by TI. Original copyright follows:
 */

/*
 *
 * linux/drivers/mtd/nand/nand_davinci.c
 *
 * NAND Flash Driver
 *
 * Copyright (C) 2006 Texas Instruments.
 *
 * ----------------------------------------------------------------------------
 *
 * SPDX-License-Identifier:	GPL-2.0+
 *
 * ----------------------------------------------------------------------------
 *
 *  Overview:
 *   This is a device driver for the NAND flash device found on the
 *   DaVinci board which utilizes the Samsung k9k2g08 part.
 *
 Modifications:
 ver. 1.0: Feb 2005, Vinod/Sudhakar
 -
 */

#include <common.h>
#include <asm/io.h>
#include <nand.h>
#include <asm/ti-common/davinci_nand.h>

/* Definitions for 4-bit hardware ECC */
#define NAND_TIMEOUT			10240
#define NAND_ECC_BUSY			0xC
#define NAND_4BITECC_MASK		0x03FF03FF
#define EMIF_NANDFSR_ECC_STATE_MASK  	0x00000F00
#define ECC_STATE_NO_ERR		0x0
#define ECC_STATE_TOO_MANY_ERRS		0x1
#define ECC_STATE_ERR_CORR_COMP_P	0x2
#define ECC_STATE_ERR_CORR_COMP_N	0x3

/*
 * Exploit the little endianness of the ARM to do multi-byte transfers
 * per device read. This can perform over twice as quickly as individual
 * byte transfers when buffer alignment is conducive.
 *
 * NOTE: This only works if the NAND is not connected to the 2 LSBs of
 * the address bus. On Davinci EVM platforms this has always been true.
 */
static void nand_davinci_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
{
	struct nand_chip *chip = mtd_to_nand(mtd);
	const u32 *nand = chip->IO_ADDR_R;

	/* Make sure that buf is 32 bit aligned */
	if (((int)buf & 0x3) != 0) {
		if (((int)buf & 0x1) != 0) {
			if (len) {
				*buf = readb(nand);
				buf += 1;
				len--;
			}
		}

		if (((int)buf & 0x3) != 0) {
			if (len >= 2) {
				*(u16 *)buf = readw(nand);
				buf += 2;
				len -= 2;
			}
		}
	}

	/* copy aligned data */
	while (len >= 4) {
		*(u32 *)buf = __raw_readl(nand);
		buf += 4;
		len -= 4;
	}

	/* mop up any remaining bytes */
	if (len) {
		if (len >= 2) {
			*(u16 *)buf = readw(nand);
			buf += 2;
			len -= 2;
		}

		if (len)
			*buf = readb(nand);
	}
}

static void nand_davinci_write_buf(struct mtd_info *mtd, const uint8_t *buf,
				   int len)
{
	struct nand_chip *chip = mtd_to_nand(mtd);
	const u32 *nand = chip->IO_ADDR_W;

	/* Make sure that buf is 32 bit aligned */
	if (((int)buf & 0x3) != 0) {
		if (((int)buf & 0x1) != 0) {
			if (len) {
				writeb(*buf, nand);
				buf += 1;
				len--;
			}
		}

		if (((int)buf & 0x3) != 0) {
			if (len >= 2) {
				writew(*(u16 *)buf, nand);
				buf += 2;
				len -= 2;
			}
		}
	}

	/* copy aligned data */
	while (len >= 4) {
		__raw_writel(*(u32 *)buf, nand);
		buf += 4;
		len -= 4;
	}

	/* mop up any remaining bytes */
	if (len) {
		if (len >= 2) {
			writew(*(u16 *)buf, nand);
			buf += 2;
			len -= 2;
		}

		if (len)
			writeb(*buf, nand);
	}
}

static void nand_davinci_hwcontrol(struct mtd_info *mtd, int cmd,
		unsigned int ctrl)
{
	struct		nand_chip *this = mtd_to_nand(mtd);
	u_int32_t	IO_ADDR_W = (u_int32_t)this->IO_ADDR_W;

	if (ctrl & NAND_CTRL_CHANGE) {
		IO_ADDR_W &= ~(MASK_ALE|MASK_CLE);

		if (ctrl & NAND_CLE)
			IO_ADDR_W |= MASK_CLE;
		if (ctrl & NAND_ALE)
			IO_ADDR_W |= MASK_ALE;
		this->IO_ADDR_W = (void __iomem *) IO_ADDR_W;
	}

	if (cmd != NAND_CMD_NONE)
		writeb(cmd, IO_ADDR_W);
}

#ifdef CONFIG_SYS_NAND_HW_ECC

static u_int32_t nand_davinci_readecc(struct mtd_info *mtd)
{
	u_int32_t	ecc = 0;

	ecc = __raw_readl(&(davinci_emif_regs->nandfecc[
				CONFIG_SYS_NAND_CS - 2]));

	return ecc;
}

static void nand_davinci_enable_hwecc(struct mtd_info *mtd, int mode)
{
	u_int32_t	val;

	/* reading the ECC result register resets the ECC calculation */
	nand_davinci_readecc(mtd);

	val = __raw_readl(&davinci_emif_regs->nandfcr);
	val |= DAVINCI_NANDFCR_NAND_ENABLE(CONFIG_SYS_NAND_CS);
	val |= DAVINCI_NANDFCR_1BIT_ECC_START(CONFIG_SYS_NAND_CS);
	__raw_writel(val, &davinci_emif_regs->nandfcr);
}

static int nand_davinci_calculate_ecc(struct mtd_info *mtd, const u_char *dat,
		u_char *ecc_code)
{
	u_int32_t		tmp;

	tmp = nand_davinci_readecc(mtd);

	/* Squeeze 4 bytes ECC into 3 bytes by removing RESERVED bits
	 * and shifting. RESERVED bits are 31 to 28 and 15 to 12. */
	tmp = (tmp & 0x00000fff) | ((tmp & 0x0fff0000) >> 4);

	/* Invert so that erased block ECC is correct */
	tmp = ~tmp;

	*ecc_code++ = tmp;
	*ecc_code++ = tmp >>  8;
	*ecc_code++ = tmp >> 16;

	/* NOTE:  the above code matches mainline Linux:
	 *	.PQR.stu ==> ~PQRstu
	 *
	 * MontaVista/TI kernels encode those bytes differently, use
	 * complicated (and allegedly sometimes-wrong) correction code,
	 * and usually shipped with U-Boot that uses software ECC:
	 *	.PQR.stu ==> PsQRtu
	 *
	 * If you need MV/TI compatible NAND I/O in U-Boot, it should
	 * be possible to (a) change the mangling above, (b) reverse
	 * that mangling in nand_davinci_correct_data() below.
	 */

	return 0;
}

static int nand_davinci_correct_data(struct mtd_info *mtd, u_char *dat,
		u_char *read_ecc, u_char *calc_ecc)
{
	struct nand_chip *this = mtd_to_nand(mtd);
	u_int32_t ecc_nand = read_ecc[0] | (read_ecc[1] << 8) |
					  (read_ecc[2] << 16);
	u_int32_t ecc_calc = calc_ecc[0] | (calc_ecc[1] << 8) |
					  (calc_ecc[2] << 16);
	u_int32_t diff = ecc_calc ^ ecc_nand;

	if (diff) {
		if ((((diff >> 12) ^ diff) & 0xfff) == 0xfff) {
			/* Correctable error */
			if ((diff >> (12 + 3)) < this->ecc.size) {
				uint8_t find_bit = 1 << ((diff >> 12) & 7);
				uint32_t find_byte = diff >> (12 + 3);

				dat[find_byte] ^= find_bit;
				MTDDEBUG(MTD_DEBUG_LEVEL0, "Correcting single "
					 "bit ECC error at offset: %d, bit: "
					 "%d\n", find_byte, find_bit);
				return 1;
			} else {
				return -1;
			}
		} else if (!(diff & (diff - 1))) {
			/* Single bit ECC error in the ECC itself,
			   nothing to fix */
			MTDDEBUG(MTD_DEBUG_LEVEL0, "Single bit ECC error in "
				 "ECC.\n");
			return 1;
		} else {
			/* Uncorrectable error */
			MTDDEBUG(MTD_DEBUG_LEVEL0, "ECC UNCORRECTED_ERROR 1\n");
			return -1;
		}
	}
	return 0;
}
#endif /* CONFIG_SYS_NAND_HW_ECC */

#ifdef CONFIG_SYS_NAND_4BIT_HW_ECC_OOBFIRST
static struct nand_ecclayout nand_davinci_4bit_layout_oobfirst = {
#if defined(CONFIG_SYS_NAND_PAGE_2K)
	.eccbytes = 40,
#ifdef CONFIG_NAND_6BYTES_OOB_FREE_10BYTES_ECC
	.eccpos = {
		6,   7,  8,  9, 10,	11, 12, 13, 14, 15,
		22, 23, 24, 25, 26,	27, 28, 29, 30, 31,
		38, 39, 40, 41, 42,	43, 44, 45, 46, 47,
		54, 55, 56, 57, 58,	59, 60, 61, 62, 63,
	},
	.oobfree = {
		{2, 4}, {16, 6}, {32, 6}, {48, 6},
	},
#else
	.eccpos = {
		24, 25, 26, 27, 28,
		29, 30, 31, 32, 33, 34, 35, 36, 37, 38,
		39, 40, 41, 42, 43, 44, 45, 46, 47, 48,
		49, 50, 51, 52, 53, 54, 55, 56, 57, 58,
		59, 60, 61, 62, 63,
		},
	.oobfree = {
		{.offset = 2, .length = 22, },
	},
#endif	/* #ifdef CONFIG_NAND_6BYTES_OOB_FREE_10BYTES_ECC */
#elif defined(CONFIG_SYS_NAND_PAGE_4K)
	.eccbytes = 80,
	.eccpos = {
		48, 49, 50, 51, 52, 53, 54, 55, 56, 57,
		58, 59, 60, 61, 62, 63,	64, 65, 66, 67,
		68, 69, 70, 71, 72, 73, 74, 75, 76, 77,
		78, 79,	80, 81, 82, 83,	84, 85, 86, 87,
		88, 89, 90, 91, 92, 93,	94, 95, 96, 97,
		98, 99, 100, 101, 102, 103, 104, 105, 106, 107,
		108, 109, 110, 111, 112, 113, 114, 115, 116, 117,
		118, 119, 120, 121, 122, 123, 124, 125, 126, 127,
		},
	.oobfree = {
		{.offset = 2, .length = 46, },
	},
#endif
};

#if defined CONFIG_KEYSTONE_RBL_NAND
static struct nand_ecclayout nand_keystone_rbl_4bit_layout_oobfirst = {
#if defined(CONFIG_SYS_NAND_PAGE_2K)
	.eccbytes = 40,
	.eccpos = {
		6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
		22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
		38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
		54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
	},
	.oobfree = {
		{.offset = 2, .length = 4, },
		{.offset = 16, .length = 6, },
		{.offset = 32, .length = 6, },
		{.offset = 48, .length = 6, },
	},
#elif defined(CONFIG_SYS_NAND_PAGE_4K)
	.eccbytes = 80,
	.eccpos = {
		6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
		22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
		38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
		54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
		70, 71, 72, 73, 74, 75, 76, 77, 78, 79,
		86, 87, 88, 89, 90, 91, 92, 93, 94, 95,
		102, 103, 104, 105, 106, 107, 108, 109, 110, 111,
		118, 119, 120, 121, 122, 123, 124, 125, 126, 127,
	},
	.oobfree = {
		{.offset = 2, .length = 4, },
		{.offset = 16, .length = 6, },
		{.offset = 32, .length = 6, },
		{.offset = 48, .length = 6, },
		{.offset = 64, .length = 6, },
		{.offset = 80, .length = 6, },
		{.offset = 96, .length = 6, },
		{.offset = 112, .length = 6, },
	},
#endif
};

#ifdef CONFIG_SYS_NAND_PAGE_2K
#define CONFIG_KEYSTONE_NAND_MAX_RBL_PAGE	CONFIG_KEYSTONE_NAND_MAX_RBL_SIZE >> 11
#elif defined(CONFIG_SYS_NAND_PAGE_4K)
#define CONFIG_KEYSTONE_NAND_MAX_RBL_PAGE	CONFIG_KEYSTONE_NAND_MAX_RBL_SIZE >> 12
#endif

/**
 * nand_davinci_write_page - write one page
 * @mtd: MTD device structure
 * @chip: NAND chip descriptor
 * @buf: the data to write
 * @oob_required: must write chip->oob_poi to OOB
 * @page: page number to write
 * @cached: cached programming
 * @raw: use _raw version of write_page
 */
static int nand_davinci_write_page(struct mtd_info *mtd, struct nand_chip *chip,
				   uint32_t offset, int data_len,
				   const uint8_t *buf, int oob_required,
				   int page, int cached, int raw)
{
	int status;
	int ret = 0;
	struct nand_ecclayout *saved_ecc_layout;

	/* save current ECC layout and assign Keystone RBL ECC layout */
	if (page < CONFIG_KEYSTONE_NAND_MAX_RBL_PAGE) {
		saved_ecc_layout = chip->ecc.layout;
		chip->ecc.layout = &nand_keystone_rbl_4bit_layout_oobfirst;
		mtd->oobavail = chip->ecc.layout->oobavail;
	}

	chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page);

	if (unlikely(raw)) {
		status = chip->ecc.write_page_raw(mtd, chip, buf,
						  oob_required, page);
	} else {
		status = chip->ecc.write_page(mtd, chip, buf,
					      oob_required, page);
	}

	if (status < 0) {
		ret = status;
		goto err;
	}

	chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
	status = chip->waitfunc(mtd, chip);

	/*
	 * See if operation failed and additional status checks are
	 * available.
	 */
	if ((status & NAND_STATUS_FAIL) && (chip->errstat))
		status = chip->errstat(mtd, chip, FL_WRITING, status, page);

	if (status & NAND_STATUS_FAIL) {
		ret = -EIO;
		goto err;
	}

err:
	/* restore ECC layout */
	if (page < CONFIG_KEYSTONE_NAND_MAX_RBL_PAGE) {
		chip->ecc.layout = saved_ecc_layout;
		mtd->oobavail = saved_ecc_layout->oobavail;
	}

	return ret;
}

/**
 * nand_davinci_read_page_hwecc - hardware ECC based page read function
 * @mtd: mtd info structure
 * @chip: nand chip info structure
 * @buf: buffer to store read data
 * @oob_required: caller requires OOB data read to chip->oob_poi
 * @page: page number to read
 *
 * Not for syndrome calculating ECC controllers which need a special oob layout.
 */
static int nand_davinci_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
				uint8_t *buf, int oob_required, int page)
{
	int i, eccsize = chip->ecc.size;
	int eccbytes = chip->ecc.bytes;
	int eccsteps = chip->ecc.steps;
	uint32_t *eccpos;
	uint8_t *p = buf;
	uint8_t *ecc_code = chip->buffers->ecccode;
	uint8_t *ecc_calc = chip->buffers->ecccalc;
	struct nand_ecclayout *saved_ecc_layout = chip->ecc.layout;

	/* save current ECC layout and assign Keystone RBL ECC layout */
	if (page < CONFIG_KEYSTONE_NAND_MAX_RBL_PAGE) {
		chip->ecc.layout = &nand_keystone_rbl_4bit_layout_oobfirst;
		mtd->oobavail = chip->ecc.layout->oobavail;
	}

	eccpos = chip->ecc.layout->eccpos;

	/* Read the OOB area first */
	chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, page);
	chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
	chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page);

	for (i = 0; i < chip->ecc.total; i++)
		ecc_code[i] = chip->oob_poi[eccpos[i]];

	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
		int stat;

		chip->ecc.hwctl(mtd, NAND_ECC_READ);
		chip->read_buf(mtd, p, eccsize);
		chip->ecc.calculate(mtd, p, &ecc_calc[i]);

		stat = chip->ecc.correct(mtd, p, &ecc_code[i], NULL);
		if (stat < 0)
			mtd->ecc_stats.failed++;
		else
			mtd->ecc_stats.corrected += stat;
	}

	/* restore ECC layout */
	if (page < CONFIG_KEYSTONE_NAND_MAX_RBL_PAGE) {
		chip->ecc.layout = saved_ecc_layout;
		mtd->oobavail = saved_ecc_layout->oobavail;
	}

	return 0;
}
#endif /* CONFIG_KEYSTONE_RBL_NAND */

static void nand_davinci_4bit_enable_hwecc(struct mtd_info *mtd, int mode)
{
	u32 val;

	switch (mode) {
	case NAND_ECC_WRITE:
	case NAND_ECC_READ:
		/*
		 * Start a new ECC calculation for reading or writing 512 bytes
		 * of data.
		 */
		val = __raw_readl(&davinci_emif_regs->nandfcr);
		val &= ~DAVINCI_NANDFCR_4BIT_ECC_SEL_MASK;
		val |= DAVINCI_NANDFCR_NAND_ENABLE(CONFIG_SYS_NAND_CS);
		val |= DAVINCI_NANDFCR_4BIT_ECC_SEL(CONFIG_SYS_NAND_CS);
		val |= DAVINCI_NANDFCR_4BIT_ECC_START;
		__raw_writel(val, &davinci_emif_regs->nandfcr);
		break;
	case NAND_ECC_READSYN:
		val = __raw_readl(&davinci_emif_regs->nand4bitecc[0]);
		break;
	default:
		break;
	}
}

static u32 nand_davinci_4bit_readecc(struct mtd_info *mtd, unsigned int ecc[4])
{
	int i;

	for (i = 0; i < 4; i++) {
		ecc[i] = __raw_readl(&davinci_emif_regs->nand4bitecc[i]) &
			NAND_4BITECC_MASK;
	}

	return 0;
}

static int nand_davinci_4bit_calculate_ecc(struct mtd_info *mtd,
					   const uint8_t *dat,
					   uint8_t *ecc_code)
{
	unsigned int hw_4ecc[4];
	unsigned int i;

	nand_davinci_4bit_readecc(mtd, hw_4ecc);

	/*Convert 10 bit ecc value to 8 bit */
	for (i = 0; i < 2; i++) {
		unsigned int hw_ecc_low = hw_4ecc[i * 2];
		unsigned int hw_ecc_hi = hw_4ecc[(i * 2) + 1];

		/* Take first 8 bits from val1 (count1=0) or val5 (count1=1) */
		*ecc_code++ = hw_ecc_low & 0xFF;

		/*
		 * Take 2 bits as LSB bits from val1 (count1=0) or val5
		 * (count1=1) and 6 bits from val2 (count1=0) or
		 * val5 (count1=1)
		 */
		*ecc_code++ =
		    ((hw_ecc_low >> 8) & 0x3) | ((hw_ecc_low >> 14) & 0xFC);

		/*
		 * Take 4 bits from val2 (count1=0) or val5 (count1=1) and
		 * 4 bits from val3 (count1=0) or val6 (count1=1)
		 */
		*ecc_code++ =
		    ((hw_ecc_low >> 22) & 0xF) | ((hw_ecc_hi << 4) & 0xF0);

		/*
		 * Take 6 bits from val3(count1=0) or val6 (count1=1) and
		 * 2 bits from val4 (count1=0) or  val7 (count1=1)
		 */
		*ecc_code++ =
		    ((hw_ecc_hi >> 4) & 0x3F) | ((hw_ecc_hi >> 10) & 0xC0);

		/* Take 8 bits from val4 (count1=0) or val7 (count1=1) */
		*ecc_code++ = (hw_ecc_hi >> 18) & 0xFF;
	}

	return 0;
}

static int nand_davinci_4bit_correct_data(struct mtd_info *mtd, uint8_t *dat,
					  uint8_t *read_ecc, uint8_t *calc_ecc)
{
	int i;
	unsigned int hw_4ecc[4];
	unsigned int iserror;
	unsigned short *ecc16;
	unsigned int numerrors, erroraddress, errorvalue;
	u32 val;

	/*
	 * Check for an ECC where all bytes are 0xFF.  If this is the case, we
	 * will assume we are looking at an erased page and we should ignore
	 * the ECC.
	 */
	for (i = 0; i < 10; i++) {
		if (read_ecc[i] != 0xFF)
			break;
	}
	if (i == 10)
		return 0;

	/* Convert 8 bit in to 10 bit */
	ecc16 = (unsigned short *)&read_ecc[0];

	/*
	 * Write the parity values in the NAND Flash 4-bit ECC Load register.
	 * Write each parity value one at a time starting from 4bit_ecc_val8
	 * to 4bit_ecc_val1.
	 */

	/*Take 2 bits from 8th byte and 8 bits from 9th byte */
	__raw_writel(((ecc16[4]) >> 6) & 0x3FF,
			&davinci_emif_regs->nand4biteccload);

	/* Take 4 bits from 7th byte and 6 bits from 8th byte */
	__raw_writel((((ecc16[3]) >> 12) & 0xF) | ((((ecc16[4])) << 4) & 0x3F0),
			&davinci_emif_regs->nand4biteccload);

	/* Take 6 bits from 6th byte and 4 bits from 7th byte */
	__raw_writel((ecc16[3] >> 2) & 0x3FF,
			&davinci_emif_regs->nand4biteccload);

	/* Take 8 bits from 5th byte and 2 bits from 6th byte */
	__raw_writel(((ecc16[2]) >> 8) | ((((ecc16[3])) << 8) & 0x300),
			&davinci_emif_regs->nand4biteccload);

	/*Take 2 bits from 3rd byte and 8 bits from 4th byte */
	__raw_writel((((ecc16[1]) >> 14) & 0x3) | ((((ecc16[2])) << 2) & 0x3FC),
			&davinci_emif_regs->nand4biteccload);

	/* Take 4 bits form 2nd bytes and 6 bits from 3rd bytes */
	__raw_writel(((ecc16[1]) >> 4) & 0x3FF,
			&davinci_emif_regs->nand4biteccload);

	/* Take 6 bits from 1st byte and 4 bits from 2nd byte */
	__raw_writel((((ecc16[0]) >> 10) & 0x3F) | (((ecc16[1]) << 6) & 0x3C0),
			&davinci_emif_regs->nand4biteccload);

	/* Take 10 bits from 0th and 1st bytes */
	__raw_writel((ecc16[0]) & 0x3FF,
			&davinci_emif_regs->nand4biteccload);

	/*
	 * Perform a dummy read to the EMIF Revision Code and Status register.
	 * This is required to ensure time for syndrome calculation after
	 * writing the ECC values in previous step.
	 */

	val = __raw_readl(&davinci_emif_regs->nandfsr);

	/*
	 * Read the syndrome from the NAND Flash 4-Bit ECC 1-4 registers.
	 * A syndrome value of 0 means no bit errors. If the syndrome is
	 * non-zero then go further otherwise return.
	 */
	nand_davinci_4bit_readecc(mtd, hw_4ecc);

	if (!(hw_4ecc[0] | hw_4ecc[1] | hw_4ecc[2] | hw_4ecc[3]))
		return 0;

	/*
	 * Clear any previous address calculation by doing a dummy read of an
	 * error address register.
	 */
	val = __raw_readl(&davinci_emif_regs->nanderradd1);

	/*
	 * Set the addr_calc_st bit(bit no 13) in the NAND Flash Control
	 * register to 1.
	 */
	__raw_writel(DAVINCI_NANDFCR_4BIT_CALC_START,
			&davinci_emif_regs->nandfcr);

	/*
	 * Wait for the corr_state field (bits 8 to 11) in the
	 * NAND Flash Status register to be not equal to 0x0, 0x1, 0x2, or 0x3.
	 * Otherwise ECC calculation has not even begun and the next loop might
	 * fail because of a false positive!
	 */
	i = NAND_TIMEOUT;
	do {
		val = __raw_readl(&davinci_emif_regs->nandfsr);
		val &= 0xc00;
		i--;
	} while ((i > 0) && !val);

	/*
	 * Wait for the corr_state field (bits 8 to 11) in the
	 * NAND Flash Status register to be equal to 0x0, 0x1, 0x2, or 0x3.
	 */
	i = NAND_TIMEOUT;
	do {
		val = __raw_readl(&davinci_emif_regs->nandfsr);
		val &= 0xc00;
		i--;
	} while ((i > 0) && val);

	iserror = __raw_readl(&davinci_emif_regs->nandfsr);
	iserror &= EMIF_NANDFSR_ECC_STATE_MASK;
	iserror = iserror >> 8;

	/*
	 * ECC_STATE_TOO_MANY_ERRS (0x1) means errors cannot be
	 * corrected (five or more errors).  The number of errors
	 * calculated (err_num field) differs from the number of errors
	 * searched.  ECC_STATE_ERR_CORR_COMP_P (0x2) means error
	 * correction complete (errors on bit 8 or 9).
	 * ECC_STATE_ERR_CORR_COMP_N (0x3) means error correction
	 * complete (error exists).
	 */

	if (iserror == ECC_STATE_NO_ERR) {
		val = __raw_readl(&davinci_emif_regs->nanderrval1);
		return 0;
	} else if (iserror == ECC_STATE_TOO_MANY_ERRS) {
		val = __raw_readl(&davinci_emif_regs->nanderrval1);
		return -1;
	}

	numerrors = ((__raw_readl(&davinci_emif_regs->nandfsr) >> 16)
			& 0x3) + 1;

	/* Read the error address, error value and correct */
	for (i = 0; i < numerrors; i++) {
		if (i > 1) {
			erroraddress =
			    ((__raw_readl(&davinci_emif_regs->nanderradd2) >>
			      (16 * (i & 1))) & 0x3FF);
			erroraddress = ((512 + 7) - erroraddress);
			errorvalue =
			    ((__raw_readl(&davinci_emif_regs->nanderrval2) >>
			      (16 * (i & 1))) & 0xFF);
		} else {
			erroraddress =
			    ((__raw_readl(&davinci_emif_regs->nanderradd1) >>
			      (16 * (i & 1))) & 0x3FF);
			erroraddress = ((512 + 7) - erroraddress);
			errorvalue =
			    ((__raw_readl(&davinci_emif_regs->nanderrval1) >>
			      (16 * (i & 1))) & 0xFF);
		}
		/* xor the corrupt data with error value */
		if (erroraddress < 512)
			dat[erroraddress] ^= errorvalue;
	}

	return numerrors;
}
#endif /* CONFIG_SYS_NAND_4BIT_HW_ECC_OOBFIRST */

static int nand_davinci_dev_ready(struct mtd_info *mtd)
{
	return __raw_readl(&davinci_emif_regs->nandfsr) & 0x1;
}

static void nand_flash_init(void)
{
	/* This is for DM6446 EVM and *very* similar.  DO NOT GROW THIS!
	 * Instead, have your board_init() set EMIF timings, based on its
	 * knowledge of the clocks and what devices are hooked up ... and
	 * don't even do that unless no UBL handled it.
	 */
#ifdef CONFIG_SOC_DM644X
	u_int32_t	acfg1 = 0x3ffffffc;

	/*------------------------------------------------------------------*
	 *  NAND FLASH CHIP TIMEOUT @ 459 MHz                               *
	 *                                                                  *
	 *  AEMIF.CLK freq   = PLL1/6 = 459/6 = 76.5 MHz                    *
	 *  AEMIF.CLK period = 1/76.5 MHz = 13.1 ns                         *
	 *                                                                  *
	 *------------------------------------------------------------------*/
	 acfg1 = 0
		| (0 << 31)	/* selectStrobe */
		| (0 << 30)	/* extWait */
		| (1 << 26)	/* writeSetup	10 ns */
		| (3 << 20)	/* writeStrobe	40 ns */
		| (1 << 17)	/* writeHold	10 ns */
		| (1 << 13)	/* readSetup	10 ns */
		| (5 << 7)	/* readStrobe	60 ns */
		| (1 << 4)	/* readHold	10 ns */
		| (3 << 2)	/* turnAround	?? ns */
		| (0 << 0)	/* asyncSize	8-bit bus */
		;

	__raw_writel(acfg1, &davinci_emif_regs->ab1cr); /* CS2 */

	/* NAND flash on CS2 */
	__raw_writel(0x00000101, &davinci_emif_regs->nandfcr);
#endif
}

void davinci_nand_init(struct nand_chip *nand)
{
#if defined CONFIG_KEYSTONE_RBL_NAND
	int i;
	struct nand_ecclayout *layout;

	layout = &nand_keystone_rbl_4bit_layout_oobfirst;
	layout->oobavail = 0;
	for (i = 0; layout->oobfree[i].length &&
	     i < ARRAY_SIZE(layout->oobfree); i++)
		layout->oobavail += layout->oobfree[i].length;

	nand->write_page = nand_davinci_write_page;
	nand->ecc.read_page = nand_davinci_read_page_hwecc;
#endif
	nand->chip_delay  = 0;
#ifdef CONFIG_SYS_NAND_USE_FLASH_BBT
	nand->bbt_options	  |= NAND_BBT_USE_FLASH;
#endif
#ifdef CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
	nand->options	  |= NAND_NO_SUBPAGE_WRITE;
#endif
#ifdef CONFIG_SYS_NAND_HW_ECC
	nand->ecc.mode = NAND_ECC_HW;
	nand->ecc.size = 512;
	nand->ecc.bytes = 3;
	nand->ecc.strength = 1;
	nand->ecc.calculate = nand_davinci_calculate_ecc;
	nand->ecc.correct  = nand_davinci_correct_data;
	nand->ecc.hwctl  = nand_davinci_enable_hwecc;
#else
	nand->ecc.mode = NAND_ECC_SOFT;
#endif /* CONFIG_SYS_NAND_HW_ECC */
#ifdef CONFIG_SYS_NAND_4BIT_HW_ECC_OOBFIRST
	nand->ecc.mode = NAND_ECC_HW_OOB_FIRST;
	nand->ecc.size = 512;
	nand->ecc.bytes = 10;
	nand->ecc.strength = 4;
	nand->ecc.calculate = nand_davinci_4bit_calculate_ecc;
	nand->ecc.correct = nand_davinci_4bit_correct_data;
	nand->ecc.hwctl = nand_davinci_4bit_enable_hwecc;
	nand->ecc.layout = &nand_davinci_4bit_layout_oobfirst;
#endif
	/* Set address of hardware control function */
	nand->cmd_ctrl = nand_davinci_hwcontrol;

	nand->read_buf = nand_davinci_read_buf;
	nand->write_buf = nand_davinci_write_buf;

	nand->dev_ready = nand_davinci_dev_ready;

	nand_flash_init();
}

int board_nand_init(struct nand_chip *chip) __attribute__((weak));

int board_nand_init(struct nand_chip *chip)
{
	davinci_nand_init(chip);
	return 0;
}